The effects of romifidine (60µg/kg) and butorphanol (40µg/kg) combination were studied in eight horses. The parameters were measured before (T0) and 10 (T1), 15 (T2), 30 (T3), 40 (T4) and 65 (T5) minutes after sedation. Heart rate, cardiac output and cardiac index decreased significantly post-treatment. A significant increase was present in pulmonary arterial pressure, pulmonary arterial wedge pressure, central...